<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Title</title>
	<style type="text/less">
		.app{
			p{
				&:first-child{
					color:red;
				}
				&:nth-child(2){
					color:yellow;
				}
				&:last-child{
					color:green;
				}
				&:hover{
					color:aqua;
				}
			}
		}
		//.app p:first-child{
		//	color:red;
		//}
		//.app p:nth-child(2){
		//	color:green;
		//}
		//.app p:last-child{
		//	color:pink;
		//}
	</style>
	<script src="lib/less.min.js"></script>
</head>
<body>
	<div class="app">
		<p>如果衣服脏了怎么办？可以娶一个老婆</p>
		<p>如果老婆贤惠，就不会自己洗了</p>
		<p>如果老婆彪悍，就学会怎么洗了</p>
	</div>
</body>
</html>